Study On Anticancer Effects Of As₂O₃ And As₂O₃ Combined With TRAIL On Lung Adenocarcinoma Cell Line A549

Objective To study the inhibition,apoptosis and underlying mechanism of proliferation inhibition and apoptosis stimulated by arsenic trioxide (AS₂O₃), AS₂O₃ combined with human tumor necrosis factor related apoptosis inducing ligand(TRAIL) on lung cancer.Methods The proliferation of lung adenocarcinoma cell line A549 cultured in vitro were divided into 6 groups randomly : The control group,1μmol/L AS₂O₃ group,10μmol/L AS₂O₃ group, 100μg/L TRAIL group, 1μmol/L AS₂O₃+100μg/L TRAIL group,10μmol/L AS₂O₃ +100μg/L TRAIL group. The cell proliferation was detected by the assay of 3-(4,5-Dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide (MTT) after treatments, Hoechest stain was applied to analyze the apoptosis effect, Flow cytometry with PI stain was used to detect the apoptosis rate after treatments. The expression of DR4 mRNA﹑DR5 mRNA﹑Survivin mRNA﹑Caspase-3 mRNA﹑MDR1 mRNA﹑MRP1 mRNA﹑NF-κB mRNA were measured by reverse transcription-polymerase chain reaction(RT-PCR). The expression of NF-κB protein were detected by Western blot. NF-κB activity was measured by ELISA.Results 1. Compared with AS₂O₃ alone , AS₂O₃ combined with TRAIL after 24h,48h and 72h could increase the inhibition ratio significantly (P<0.05),and the inhibition rate was related to the concentration and action time of AS₂O₃. 2. After AS₂O₃ and TRAIL were applied 48h, more apoptosis cell could be seen than AS₂O₃ or TRAIL by Hoechest stain and flow cytometry. 3. RT-PCR showed that the expression of Caspase-3 mRNA were up-regulated in AS₂O₃ group, the expression of DR4 mRNA﹑DR5 mRNA﹑Caspase-3 mRNA were up-regulated by combined group; the expression of Survivin mRNA,MDR1 mRNA,MRP1 mRNA,NF-κB mRNA were down-regulated in combined group; 4. Western blot showed that the expression of NF-κB protein were down-regulated by combined group; 5. ELISA showed that the activity of NF-κB was inhibited by combined group.Conclusion This vitro study demonstrated that AS₂O₃ combined with TRAIL could clearly synergistic inhibit the lung adenocarcinoma A549 cell proliferation and induce apoptosis. That possible mechanism might be related to increase the expression of Caspase-3mRNA to promote apoptosis of cancer cells by death receptor signaling pathway and mitochondrial signaling pathway; down-regulate the expression of Survivin mRNA and MDR1 mRNA to induce apoptosis by inhibition of NF-κB signaling pathway. This study has reported that the antitumor activity was reinforced by AS₂O₃ conbined TRAIL in vitro.These results have provided a foundation for treatment of lung cancer by AS₂O₃ combined TRAIL in clinic.